139858 ÷ 51 
The aim is to understand the frequency of 51 in 139858.

Step 1:
If we divide 1 by 51, we get 0 and a remainder of 1.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 1 and we're left with 1.
Grab the next digit (3) from the dividend, add it to 1, then carry on: 13 / 51

Advancing to step 2:
When dividing 13 by 51, we get 0 with a remainder of 13.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 13, we get 13.
Include the next digit (9) from the dividend after 13, then repeat: 139 / 51

Moving on to step 3:
139 divided by 51 is 2 with a remainder of 37.
The next digit of our result is 2. 
Result so far: 2.0
If we take 102 away from 139, we end up with 37.
Take the next digit (8) from the dividend and append it to 37, then repeat: 378 / 51

Let's proceed to step 4:
The number 51 fits into 378 7 times, leaving a remainder of 21.
The number 7 becomes the next digit in our result. 
Result so far: 27.0
Subtract 357 from 378 to get 21.
Take the next digit (5) from the dividend and append it to 21, then repeat: 215 / 51

Step 5:
When dividing 215 by 51, we get 4 with a remainder of 11.
Use 4 as the next digit of our solution. 
Result so far: 274.0
Deduct 204 from 215 and we're left with 11.
Fetch the next digit (8) from the dividend, attach it to 11 and continue: 118 / 51

Going ahead to step 6:
When dividing 118 by 51, we get 2 with a remainder of 16.
Write down 2 as next digit of the result. 
Result so far: 2742.0
Deduct 102 from 118 and we're left with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Step 7:
The number 51 fits into 160 3 times, leaving a remainder of 7.
Use 3 as the next digit of our solution. 
Result so far: 2742.3
Deduct 153 from 160 and we're left with 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Advancing to step 8:
If we divide 70 by 51, we get 1 and a remainder of 19.
Use 1 as the next digit of our solution. 
Result so far: 2742.31
Subtracting 51 from 70 leaves us with 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Advancing to step 9:
51 goes into 190 3 times with a remainder of 37.
The next digit of our result is 3. 
Result so far: 2742.313
Subtract 153 from 190 to get 37.
Since there are no more digits in the dividend, we add a zero to the remainder making it 370, and continue the process.

Going ahead to step 10:
370 divided by 51 is 7 with a remainder of 13.
The number 7 becomes the next digit in our result. 
Result so far: 2742.3137
If we subtract 357 from 370, we get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Going ahead to step 11:
If we divide 130 by 51, we get 2 and a remainder of 28.
Record the quotient 2 as the next digit in the result. 
Result so far: 2742.31372
The remainder is 28 after subtracting 102 from 130.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

Step 12:
If we divide 280 by 51, we get 5 and a remainder of 25.
Put 5 as the next digit of the answer. 
Result so far: 2742.313725
Subtracting 255 from 280 leaves us with 25.
Since there are no more digits in the dividend, we add a zero to the remainder making it 250, and continue the process.

Advancing to step 13:
The number 51 fits into 250 4 times, leaving a remainder of 46.
Record the quotient 4 as the next digit in the result. 
Result so far: 2742.3137254
If we take 204 away from 250, we end up with 46.
Since there are no more digits in the dividend, we add a zero to the remainder making it 460, and continue the process.

Advancing to step 14:
The number 51 fits into 460 9 times, leaving a remainder of 1.
Record the quotient 9 as the next digit in the result. 
Result so far: 2742.31372549
If we subtract 459 from 460, we get 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

The quotient of the division is 2742.31372549, and the remainder is 1e-09.